Coronary Artery Crossing: A Case Report and Literature Review

Background: Coronary artery crossing (CACr) constitutes a rare but clinically relevant anomaly of intrinsic coronary arterial anatomy. Current literature on this subject comprises isolated case reports and one case series. The purpose of this report is to present all cases of CaCr that have been reported in the English literature, highlighting its clinical implications. Case: We present the case of a patient with intermittent chest discomfort associated with psychological stress and evidence of crossing between the left anterior descending (LAD) artery and the first diagonal artery (DgA) on invasive coronary angiography. Myocardial bridging was also noted in the mid LAD artery but not at the crossing point or any other crossing artery segments, and produced obstructive (≥50%) dynamic lumen compromise. The patient was discharged in good condition and was prescribed aspirin, a statin, and diltiazem. Conclusions: This review included 24 records that represented 27 patients, including the one presented in this report. The anomaly has been predominantly diagnosed in male patients and the diagnosis has predominantly been made using computed tomography coronary angiography. The most frequent CACr pattern revealed in 12 patients (44%) was a crossing between the LAD and left circumflex arteries while the second most frequent CACr pattern revealed in six patients (22%) was a crossing between the LAD artery and a DgA. There were five cases (19%) with evidence of an intramyocardial course, either at the point of vessel crossover or beyond that point. The crossing coronary arteries themselves were found to have atherosclerotic lesions in three patients (11%). Even though CaCr has not been associated with any clinical repercussions, cardiologists and cardiac surgeons should bear knowledge of this anomaly not only for diagnostic purposes when performing coronary artery angiograms but also in order to properly select and execute a revascularization procedure. Furthermore, CaCr may be associated with clinically relevant, functional coronary artery abnormalities such as spasm affecting the segments of the arteries crossing over each other or having an intramyocardial course. Unique patterns of coronary blood flow and wall shear stress may also be created at the crossover area, potentially increasing the risk of developing atherosclerosis.